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I've a pair of Maggie .7's and considering some modifications, yet I see virtually nothing here about it -- not that anyone's search engine will hone in on a 2-character model name let alone where one character is punctuation!
So, has anyone done some wiring and/or crossover modifications to the .7?
Tabs:
I've read a few posts advising NOT to solder wires to the tabs attached to the drivers as it can easily melt the mylar. Yet I see screw clamps that attach the foil leads to the tabs.
* Why not just unscrew the foil from the tab and then solder to the tab?
* Is the plastic mount for the tabs not heat resistant? It looks like I can slide the tabs out from the plastic mount and solder that way. Any issues there?
Terminals:
These are tinned brass, though the fixing nut and set screw are ferrous steel.
* Can replace the nut with brass or just replace the posts with ones having higher copper content, better grip on banana/z-plugs, and can handle spades as well.
Wiring Generally:
Is 16ga copper in mostly 10" lengths, soldered at crossover end, and attached to push tabs on the other end.
* The crimping and push tabs fit is proper, but can gain a little through replacing push tabs with soldered connections where appropriate. The ring termainls are still just screwed down tight against the speaker terminals, so can be removed as required.
* It would seem that 16ga is decent for the tweeter side though could probably improve on the wire quality.
* For general amplifier input through the speaker terminals to the crossover 14ga is probably better and short enough that larger wire may not be required, though 12ga couldn't hurt if your soldering skills can handle that heavy a wire without damaging something with heat.
Jumpers:
Same as always. Poor quality and the sound suffers.
* Can replace with good quality copper cable jumpers or just move both wires on the back to one terminal, bypassing the jumper.
* If having a sufficient amplifier that won't clip, can also bypass the tweeter fuse for increase in SQ.
Sock:
I notice this sock has no seams on the bottom, just a continuous loop, so unscrewing the side trim and then removing the staples under that trim is the way, then slide top and bottom of fabric off of the panel.
The fabric is stretchy and strong enough that for some work one only need remove the staples halfway up on the crossover side and then can push it out of the way.
--
Theories tickle the brain, but listening to the music is more satisfying.
Calyx 24/192 DAC, Classe Audio 30 pre/70 amp balanced. Proac Response 1sc w/Ansar caps. MIT MH-750 spkr, HT Truthlink XLR, Roller bearings, cups, inner tubes.
Follow Ups:
you could replace the stock caps with something more energetic but those types of things are always an adventure..When I replaced the caps on my 1.6's it was based on different folks who posted various brands of capacitors.When the foil series came along I've seen very little post involving surgery on any of the 'i' series so it's pretty much an open frontier.
Edits: 07/17/21 07/17/21 07/17/21
As best I can discern, there is no difference in the crossovers of the non-i models v. the i models. Beyond modifying the crossover, the usual Maggie tweaks (wood frames, losing the jumpers and fuse, etc) would be the same and there would not be a reason to post.
I did contemplate doing surgery on the 3.7i but decided against for two reasons: 1) The 3.7i (and 3.7) has a pile of caps and replacing with "higher grade" would cost a fortune and the expected improvement would be small and 2) conversion to a parallel crossover topology with the goal of going to biamping was more difficult than I anticipated. This would have been relatively cheap as I already owned two identical amplifiers and an active crossover (XM-44). While in theory any series XO can be converted to a parallel XO in actuality this was not the case. The reason being that a series XO always results in a flat output but my attempts at an equivalent parallel configuration resulted in a "bump" at the XO frequency. I did work out a parallel XO for the 1.7(i) but, since I didn't own a pair, it was just an exercise of the mind.P.S. For Davey: The failure to get a flat output curve with the 3.7, I believe, was due to the mid-driver being 8 ohm while the woofer and tweeter were 4 ohm. When I made the impedance of all 3 drivers the same the curve flattened out.
I married the perfect woman - the downside is that everything that goes wrong is my fault.
Edits: 07/17/21
Are you sure the 3.7 has an 8 ohm midrange driver??
Dave.
Yes, I measured it myself and also discussed it with Wendall who confirmed my measurements.
I married the perfect woman - the downside is that everything that goes wrong is my fault.
Neo - check out Joe Schmo's post a couple rows below.
Nt
It has great potential but the treble was pretty mediocre until I replaced the stock tweeter jumper and then bypassed it and the fuse. Still needs better clarity and transparency in mids and highs but getting close.
Bass and dynamics really benefitted by playing with toe-in, changes as little as 0.5". But I imagine could do better with higher gauge wire than 16awg.
But that's not what this thread is about.
--
Theories tickle the brain, but listening to the music is more satisfying.
mRendu, Calyx 24/192 DAC, Neurochrome Modulus-686, Pass design B1rev2 buffer, Magnepan .7, EWA LS-25 spkr, HT Truthlink
Sorry if you meant the supplied resistors in the jumper position. I did however find them useful when the speakers were being broken in;
also if you are 'under powering' the speakers the tweeter will never bloom just surely as the bass section will not.
I have the 1.7; there is no 'tweeter jumper'. I replaced the jumper with an inductor, that smooths out the entire system which gives depth and space. I had found the 'tweet bright for my room, rather too alive. The same elements are used in both speakers, the latter obviously having different cross over points.
Good luck.
Well, there certainly IS a tweeter jumper. :)
When you replaced the jumper with an inductor you were inserting it into the tweeter path only.
My goodness.
Dave.
Thank you for correcting me! Good to hear from you.
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